Expert: Griff Ruby - 1/29/2005

Question
What vulnerability in attending mass offered by priest associated with sedevacantist organization (or independent)  versus SSPX?

Answer
In each case, the main "risk" is the same that it is possible that some priests of either category might at times be reckless in condemning their priestly peers within the other category for merely holding such position/membership.  Apart from that, these are priests who are carrying out their responsibilities with respect to the souls committed to their care exactly as priest ought.
One other proviso is that when one says "sedevacantist" one has to ask whether we are speaking of a "sedevacantist" in one of the recognised orders with bishops (e. g. SSPV, CMRI, Trento Priests in Mexico, and so forth) or merely an independent priest who happens to be a sedevacantist.  From my experience, the priests with organizations and bishops behind them tend to be better behaved than those on their own as the latter have no real accountability, though some few of the latter sort do well also.
Every group has some small risk from this same direction, though many or most individual priests understand well enough to rise above the temptation.  Indultarians tend to say "We're legit, and no one else is."  The first part is true, the second is false.  The SSPX has its reasons for preaching some manner of "avoidance" of either Indult or sedevacantist clergy, and sedevacantists can sometimes assume that saying Mass "una cum" John Paul II (as both SSPX'ers and Indultarians do) connects them to his heresies and scandals, which it really does not.
Since it sounds like you have something of a choice, it would be best to simply go with looking at each priest himself, how well he carries out his vocation.  As long as you are conscious of the possible limitations of each sort of priest, and as long as they don't otherwise flagrantly fall into error or scandal, there really are no serious concerns whichever way you decide is best.
If you still can't choose, then one should go with whichever has a congregation of people one likes better or which has their church closer etc.  But the most important is to look at the individual priest himself and see whose priest happens to be seasoned, balanced, reasonable, approachable, and unwilling to criticize his fellow clergy.  Look for a priest who is clearly more interested in helping souls find salvation than in proving he's right about whatever position he has taken as against all others.
Understand too that all "theories" as to whether we have a pope or not are just that: "theories."  At times, a priest will speak in favor of the theory he personally favors, and again, another bad sign would be if he keeps harping on it all the time.  An occasional passing mention of it is appropriate and can be taken with a grain of salt at that.
Anyway, I hope this helps.  God bless!